The Resurection

The 5 amp board is resurected.
After managing to locate parts over here in the UK, I still had no luck in getting the board up and running, after discussing the matter with Paul Corner I took up his kind offer to look at it with a scope to see what was happening, so I drove down last Monday (Newcastle to Norwich 510 mile round trip) arriving at about 10.30,
in the morning, A steaming pot of hot coffee was pushed in my hand, (much appreciated after the drive) and much mulling over of the board took place, over the next six hours it was duly scoped prodded parts replaced,and brought back to full working order, (miracles do happen) in spite of the No1 scope going down, and having to dig out the first reserve, although we could only run it at one amp as there were no heat sinks fitted.
During a short break in the proceedings I was dragged of into the Workshop to see his nice little Bridgeport Mill, (little being not quite the right word, I thought I was short of space, do we all suffer from this problem,) its not exactly a bench model, (about 2 tons) but a nice piece of kit, I also saw the flywheel with curved spokes that he had cut from solid on the Mill without a rotary table, a nice job.
On Tuesday I fitted the heatsinks and took all axis up to 3.3volts which is about right for my 4.5 amp motors and tried all axis out, X and Y were perfect but on Z the motor was all over the place, I replaced a couple of mossfets, the chips, resoldered all the joints on that axis, but it was still the same,
I set the motor running at 3.3 volts and while prodding and poking around, found that if i put a little bit of pressure on the plug onto the four pin header the motor kicked in as sweet as a nut, I resoldered everything in that area but still nothing, while moving this plug about I accidentaly bent the two wires from the 555 timer down very close to the board, and it ran OK, it was then I realised that it was interference as this axis is the closest one to the 555 chip, I duly tried Tims patent aluminium foil trick around the two wires, and there it was running like a Swiss watch.
Many thanks again to Paul Corner without who's help I would have still been in the dark, I have learnt a little bit along the way ( must get one of those scope things).

Next year
Must learn something about electronics, must not bother Paul Corner, I have got a Sherline to convert to CNC (may end up as an engraver), possibly another 5amp board from Dan for a CNC grinder project, may look for a better quality Mill to CNC retrofit, but nothing to huge,

Best Wishes to all
Peter Smith